How do I morph between unrelated meshes
Is your medical imagery made only of vertex (no planes)? If this is the case, you could morph one to another by using a particle system.


add a particle system to each object, with the same number of particles
create one additional object with the same number of particles
add Physics > keys in the last created object's particle system, create a key for each of your medical imagery objects.


Here is a complete tutorial about this.
https://www.youtube.com/watch?v=lPCs4XbGth8

Hope it helps!